George,
HSB tolerance for warm water starts to wane as they reach larger sizes. What does your pond have for maximum depth and does it develop a thermocline in the summer? If you are catching enough of them you can cull out the slow-growers by angling in order to keep overall biomass in check. If you go to your local craft store they may have something called "pom-poms" which little girls use to decorate their shoe laces. If you're really lucky they'll have the brown ones, which, when threaded on a hook look a lot like Aquamax Grower 600. It's great for fly fishing and you can catch the fish at will. Subsequent stockings can be marked by cutting off a corner of the tail during stocking. This will heal but leave a tell-tale mark for future identification. Later on this will help you to differentiate between a slow growing age-3 and a fast growing age-2 fish. Just remember, it's not how many HSB you have in the pond...it's how many pounds of fish per acre that will determine growth potential. Be VERY careful not to let the overall biomass get out of control!
